Min Wang

Chinese Academy of Sciences | CAS · Institute of Vertebrate Paleontology and Paleoanthropology

Ornithuromorpha is the most inclusive clade containing extant birds but not the Mesozoic Enantiornithes. The early evolutionary history of this avian clade has been advanced with recent discoveries from Cretaceous deposits, indicating that Ornithuromorpha and Enantiornithes are the two major avian groups in Mesozoic. Here we report on a new ornithu...

The Early Cretaceous is a critical interval in the early history of birds. Exceptional fossils indicate that important evolutionary novelties such as a pygostyle and a keeled sternum had already arisen in Early Cretaceous taxa, bridging much of the morphological gap between Archaeopteryx and crown birds. However, detailed features of basal bird evo...

Enantiornithes are the most successful clade of Mesozoic birds. Here, we describe a new enantiornithine bird, Cruralispennia multidonta gen. et sp. nov., from the Protopteryx-horizon of the Early Cretaceous Huajiying Formation of China. Despite being among the oldest known enantiornithines, Cruralispennia displays derived morphologies that are unex...

Powered flight evolved independently in vertebrates in the pterosaurs, birds and bats, each of which has a different configuration of the bony elements and epidermal structures that form the wings1,2. Whereas the early fossil records of pterosaurs and bats are sparse, mounting evidence (primarily from China) of feathered non-avian dinosaurs and ste...

The transformation of the bird skull from an ancestral akinetic, heavy, and toothed dino-saurian morphology to a highly derived, lightweight, edentulous, and kinetic skull is an innovation as significant as powered flight and feathers. Our understanding of evolutionary assembly of the modern form and function of avian cranium has been impeded by th...

The morphology of the pectoral girdle, the skeletal structure connecting the wing to the body, is a key determinant of flight capability, but in some respects is poorly known among stem birds. Here, the pectoral girdles of the Early Cretaceous birds Sapeornis and Piscivorenantiornis are reconstructed for the first time based on computed tomography...

We describe six specimens consisting of cranial remains and associated partial presacral axial series belonging to ornithuromorph birds from the Changma locality of the Lower Cretaceous Xiagou Formation of northwestern Gansu Province, China. Comparison among specimens is limited by the paucity of overlapping elements, their differing exposed views,...

A unique form of melanosomes contributing to brilliant iridescent colors in modern bird feathers, previously unknown in fossil birds, is identified in the Early Cretaceous bird Eoconfuciusornis. The discovery highlights the complexity of plumage color nanostructures utilized early in bird evolution as far back as 130 million years ago.

Pectoral girdle morphology is a key determinant of flight capability, but in some respects is poorly known among stem birds. Here, we reconstruct the pectoral girdles of the Early Cretaceous birds Sapeornis and Piscivorenantiornis based on computed tomography and three-dimensional visualization, revealing key morphological details. Enantiornithines...

The globally distributed extinct clade Enantiornithes comprises the most diverse early radiation of birds in the Mesozoic with species exhibiting a wide range of body sizes, morphologies, and ecologies. The fossil of a new enantiornithine bird, Brevirostruavis macrohyoideus gen. et sp. nov., from the Lower Cretaceous Jiufotang Formation in Liaoning...

Enantiornithes are the most successful group of Mesozoic birds, arguably representing the first global avian radiation,1, 2, 3, 4 and commonly resolved as the sister to the Ornithuromorpha, the clade within which all living birds are nested.1,3 The wealth of fossils makes it feasible to comparatively test evolutionary hypotheses about the pattern a...

The Lower Cretaceous Jiufotang Formation in western Liaoning Province, northeastern China contains important vertebrate fossils of the late Jehol Biota, e.g., the four-winged non-avian dinosaur Microraptor. This formation documents the late phase of the Jehol Biota, producing the most abundant fossil records of the Mesozoic birds. However, the prec...

The Early Cretaceous Jehol Biota is a terrestrial lagerstätte that contains exceptionally well-preserved fossils indicating the origin and early evolution of Mesozoic life, such as birds, dinosaurs, pterosaurs, mammals, insects, and flowering plants. New geochronologic studies have further constrained the ages of the fossil-bearing beds, and recent...

Here we report a new avian fossil from the Late Miocene Linxia Basin, Northwest China, with exceptional soft-tissue preservation. This specimen preserves parts of cervical vertebrae and tracheal rings that are typically ostrich-like, but cannot be diagnosed at the species level. Therefore, the fossil is referred to Struthio sp. The new specimen was...

Supplementary Information for "Cretaceous bird with dinosaur skull sheds light on avian cranial evolution"

The recent finding of a fossil entombed in a Late Cretaceous amber-Oculudentavis khaungraae-was claimed to represent a humming bird-sized dinosaur. Regardless of the intriguing evolutionary hypotheses about the bauplan of Mesozoic dinosaurs (including birds) posited therein, this enigmatic animal demonstrates various morphologies resembling lizards...

Here we report a new avian fossil from the Late Miocene Linxia Basin, Northwest China, with exceptional soft-tissue preservation. This specimen preserves parts of cervical vertebrae and tracheal rings that are typically ostrich-like, but cannot be diagnosed at the species level. Therefore, the fossil is referred to Struthio sp. The new specimen was...

Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in...

The origin of birds from non-avian theropod dinosaurs is one of the greatest transitions in evolution. Shortly after diverging from other theropods in the Late Jurassic, Mesozoic birds diversified into two major clades—the Enantiornithes and Ornithuromorpha—acquiring many features previously considered unique to the crown group along the way. Here,...

Yanornithidae is an Early Cretaceous ornithuromorph clade that preserves the oldest direct evidence indicative of a piscivorous diet in avian evolution. The family hitherto contained only a single genus Yanornis and two putative species. The yanornithids are readily distinguishable from other Mesozoic avians in having a long rostrum packed with num...

We describe a new enantiornithine specimen from the Lower Cretaceous Jiufotang Formation of the Jehol Biota, northeastern China, which can be assigned to the species Piscivorenantiornis inusitatus. The new specimen confirms the presence of the unusual articulation of the cervical vertebrae that characterizes P. inusitatus. The disarticulated bony e...

The remains of ovarian follicles reported in nine specimens of basal birds represents one of the most remarkable examples of soft-tissue preservation in the Early Cretaceous Jehol Biota. This discovery was immediately contested and the structures alternatively interpreted as ingested seeds. Fragments of the purported follicles preserved in an enant...

Feather molt is an important life-history process in birds, but little is known about its evolutionary history. Here, we report on the first fossilized evidence of sequential wing feather molt, a common strategy among extant birds, identified in the Early Cretaceous four-winged dromaeosaurid Microraptor. Analysis of wing feather molt patterns and e...

The Lower Cretaceous Huajiying Formation of the Sichakou Basin in northern Hebei Province, northern China contains key vertebrate taxa of the early Jehol Biota, e.g., Protopteryx fengningensis , Archaeornithura meemannae , Peipiaosteus fengningensis , and Eoconfuciusornis zhengi . This formation arguably documents the second-oldest bird-bearing hor...

Living birds are unique among vertebrates in the formation of a female-specific bone tissue called medullary bone (MB) that is strictly associated with reproductive activity. MB is a rapidly mobilized source of calcium and phosphorus for the production of eggshell. Among living taxa, its skeletal distribution can be highly extensive such that it ev...

Background: Tooth morphology within theropod dinosaurs has been extensively investigated and shows high disparity throughout the Cretaceous. Changes or diversification in feeding ecology, i.e., adoption of an herbivorous diet (e.g., granivorous), is proposed as a major driver of tooth evolution in Paraves (e.g., Microraptor, troodontids and aviala...

Bohaiornithidae is currently the most diverse recognized family of Early Cretaceous enantiornithines, with unique morphology of the rostrum and pedal digits. Here we describe a second specimen of the bohaiornithid Longusunguis kurochkini from the Jiufotang Formation. This specimen provides new anatomical information regarding this taxon, in particu...

The Jehol Biota is an Early Cretaceous terrestrial fossil assemblage of paramount significance, and its core distribution areas are western Liaoning, northern Hebei, and southeastern Inner Mongolia. Despite with a research history of more than 150 years, it started yielding important fossils until early 1990s, which include feathered dinosaurs, ear...

Recent finding of a fossil, Oculudentavis khaungraae Xing et al. 2020, entombed in a Late Cretaceous amber was claimed to represent a humming bird-sized dinosaur [1]. Regardless the intriguing evolutional hypotheses about the bauplan of Mesozoic dinosaurs (including birds) posited therein, this enigmatic animal, however, demonstrates various lizard...

Molting-the process replacing one plumage with another-is a critically important biological function in Aves. This process annually replaces the feather coat, damaged by normal wear and tear, produces ontogenetic changes in feathering, and produces alternate breeding plumages associated with reproductive activity in adults. Immature, growing feathe...

Living birds are unique among vertebrates in the formation of a female-specific bone tissue called medullary bone (MB) that is strictly associated with reproductive activity. MB is a rapidly mobilized source of calcium and phosphorus for the production of eggshell. Among living taxa, its skeletal distribution can be highly extensive such that it ev...

The Early Cretaceous basal birds were known largely from just two-dimensionally preserved specimens from north-eastern China (Jehol Biota), which has hindered our understanding of the early evolution of birds. Here, we present a three-dimensionally-preserved skeleton (FPDM-V-9769) of a basal bird from the Early Cretaceous of Fukui, central Japan. U...

The earliest record of the Ornithuromorpha, which includes crown birds, is currently known from the Early Cretaceous Jehol Biota in north-eastern China. Here we describe a new ornithuromorph bird, Mengciusornis dentatus gen. et sp. nov., from the Jiufotang Formation of this biota. Mengciusornis preserves a suite of morphological features exclusivel...

During the last decade, several Bohaiornis -like enantiornithine species—and numerous specimens—have been recognized from the celebrated Jehol Biota of northwestern China. In this paper, we describe the anatomy of another “bohaiornithid” species from the 125 million-year-old Yixian Formation of Liaoning Province, China. The new taxon differs from p...

Recently, comprehensive morphological datasets including nearly all the well-recognized Mesozoic birds became available, making it feasible for statistically rigorous methods to unveil finer evolutionary patterns during early avian evolution. Here, we exploited the advantage of Bayesian tip dating under relaxed morphological clocks to estimate both...

Change history: In this Letter, it should have been acknowledged that the silhouettes of Scansoriopterygidae in Fig. 3a were modified from a sketch by Jaime Headden. The original Letter has been corrected online.

During the dinosaur–bird transition, feathers of bird ancestors must have been molecularly modified to become biomechanically suitable for flight. We report molecular moieties in fossil feathers that shed light on that transition. Pennaceous feathers attached to the right forelimb of the Jurassic dinosaur Anchiornis were composed of both feather β-...

We report a new small enantiornithine, Shangyang graciles gen. et sp. nov., based on a nearly complete and articulated skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, north-eastern China. Shangyang has premaxillae that are completely fused rostrally as well as along the frontal processes, a previously unrecognized condi...

Confuciusornithidae is the clade of Early Cretaceous birds most rich in materials and plays a central role in our understanding of the evolution of avian horny beaks and pygostyles. A handful of specimens demonstrate that this avian group is distinguishable from other basal birds by their robust, toothless upper and lower jaws, a fused scapulocorac...

The Confuciusornithiformes is a basal clade of Early Cretaceous birds that includes the oldest and most basal birds with a toothless beak and an abbreviated bony tail. Over the last two decades, thousands of specimens have been collected, more than for any other group of Mesozoic birds or non-avian dinosaurs. Ten species separated into four genera...

We describe a specimen of the basal ornithuromorph Archaeorhynchus spathula from the Lower Cretaceous Jiufotang Formation with extensive soft tissue preservation. Although it is the fifth specimen to be described, unlike the others it preserves significant traces of the plumage, revealing a pintail morphology previously unrecognized among Mesozoic...

Early members of the clade Pygostylia (birds with a short tail ending in a compound bone termed “pygostyle”) are critical for understanding how the modern avian bauplan evolved from long-tailed basal birds like Archaeopteryx. However, the currently limited known diversity of early branching pygostylians obscures our understanding of this major tran...

Recently, comprehensive morphological datasets including nearly all the well-recognized Mesozoic birds become available, making it feasible for statistically rigorous methods to unveil finer evolutionary patterns during early avian evolution. However, few quantitative and statistical studies have yet been performed. Here, we exploited the advantage...

The Confuciusornithiformes is a basal clade of Early Cretaceous birds that includes the oldest and most basal birds with a toothless beak and an abbreviated bony tail. Over the last two decades, thousands of specimens have been collected, more than for any other group of Mesozoic birds or non-avian dinosaurs. Ten species separated into four genera...

Bird skeletons exhibit remarkable modifications that allow for flight. The most distinguishable features are the fusion of the bones in the hand, feet, and pelvis into composite rigid and bony structures. However, the historical origins of these avian bone fusions remain elusive because of the rarity of transitional fossils and developmental studie...

Birds have evolved on the planet for over 150 million years and become the most speciose clade of modern vertebrates. Their biological success has been ascribed to important evolutionary novelties including feathers, powered flight, and respiratory system, some of which have a deep evolutionary history even before the origin of birds. The last two...

A fish-eating enantiornithine bird with a gastric pellet composed of fish bones has recently been reported from the Lower Cretaceous Jiufotang Formation of Liaoning Province, northeastern China. Along with other discoveries, this specimen reveals that distinct features of modern avian digestive system were well established in those early birds. On...

We report on an exceptional specimen of Eoconfuciusornis preserving rare soft-tissue traces of the ovary and wing. Ovarian follicles preserve a greater hierarchy than observed in Jeholornis and enantiornithines, suggesting confuciusornithiforms evolved higher rates of yolk deposition in parallel with the neornithine lineage. The preserved soft tiss...

Description of morphological character used in the phylogenetic analysis (from Wang et al. 2015)

The six most parsimonious trees resultant from the phylogenetic analysis.

Dataset of 262 morphological characters for the 59 taxa included in the phylogenetic analysis.

Supplementary Figures, Supplementary Tables, Supplementary Notes and Supplementary References

The zygoma (called jugal bar) in modern birds accounts for a large portion of the ventral margin of the cranium. As a delicate and rod-like element, the jugal bar is functionally integrated into the avian cranial kinesis, a unique property that allows the beak to be elevated or depressed with respect to the braincase and thus distinguishes birds fr...

Here we describe the well-preserved skull of a juvenile specimen of Sapeornis, STM 16-18. Only the tail and hindlimb plumage of this specimen have been previously described. It preserves what we consider to be the complete dentition of Sapeornis with four premaxillary teeth, three maxillary teeth and two tiny dentary teeth on each side, the latter...

Microbodies associated with feathers of both nonavian dinosaurs and early birds were first identified as bacteria but have been reinterpreted as melanosomes. Whereas melanosomes in modern feathers are always surrounded by and embedded in keratin, melanosomes embedded in keratin in fossils has not been demonstrated. Here we provide multiple independ...

Mr Nick Gardner (Potomac State College of West Virginia University) has informed us that the name Bellulia which we used to describe a new genus of basal ornithuromorph bird from the Early Cretaceous (Wang, Zhou & Zhou, 2016) is preoccupied by a species of moth. This was described by Fibiger (2008) as a genus of moths of the Erebidae family, and th...

Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptiona...